JP2992897B2 - Hydraulic control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention transmits torque of an engine output shaft to a load drive shaft, and the rotational speed of the engine output shaft with respect to the rotational speed of the load drive shaft. The present invention relates to an automatic transmission that automatically switches the gear ratio, that is, the gear ratio, and more particularly to pressure control of a brake and a clutch in a transmission at the time of gear shifting to suppress a gear shift shock.

2. Description of the Related Art In this type of automatic transmission, when shifting from one speed stage to another one speed stage, at least one hydraulic pressure of a brake and a clutch in the automatic transmission is released, and the other at least one speed stage is released. Although the hydraulic pressure is supplied to each of the hydraulic pumps, a shift shock is likely to occur due to such switching of the hydraulic pressure.

Therefore, conventionally, an accumulator is connected to the brake and clutch of the automatic transmission to reduce the back pressure of the accumulator,
The pressure is adjusted so as not to cause a shock at the time of shifting (for example, JP-A-56-138553).

However, since this pressure adjustment is performed by a mechanical valve, the pressure adjustment is relatively coarse, and it is desired that the pressure be adjusted more smoothly and appropriately.

Therefore, in the automatic transmission disclosed in JP-A-61-149657,
The hydraulic circuit is equipped with a pressure control valve that is electrically energized to adjust the back pressure of the accumulator. The throttle valve opening, shift mode, engine oil temperature, engine coolant temperature, engine intake temperature, oil temperature of automatic transmission, Correspond to at least one of the selected position of the pattern select switch, engine torque, engine speed, engine supercharging pressure, engine fuel injection amount, output shaft torque of automatic transmission and output shaft rotation speed of automatic transmission. The energization duty value of the pressure control valve by the electric energization is determined, and the pressure control valve is energized with the energization duty value to determine the back pressure corresponding to the energization duty in the accumulator.

According to this, since the back pressure of the accumulator can be finely adjusted by the current value (energization duty) flowing through the pressure control valve, a more appropriate back pressure can be set in the accumulator and can be adjusted smoothly.

(Problems to be Solved by the Invention) By the way, in the shift, the gear ratio of the automatic transmission is switched by releasing the speed stage before the shift and entering the speed stage after the shift. If they do not match, a shift shock or engine blowing will occur.

For example, when shifting from the second speed to the first speed, the first speed is the speed stage selected when the vehicle running load is the largest, so the brake or clutch engaged in the first speed has the maximum vehicle drive. A high oil pressure transmitting torque is provided.

However, if this high oil pressure is applied to the brake or the clutch simultaneously with the start of the conversion to the first speed, a large shock occurs.

When the shift lever (manual valve) is switched from the drive D range or the second S range to the low L range, the engagement hydraulic pressure of the brake or the clutch is switched to a hydraulic pressure high enough to transmit the maximum torque. A momentary change (also a shock) occurs.

A first object of the present invention is to suppress a large shock when shifting to the first speed, and a second object is to suppress a shock when switching the manual valve from the D or S range to the L range. It is to suppress.

[Configuration of the invention]

(Means for Solving the Problems 1) A first invention of the present application is to provide at least a first gear, a second gear and a third gear which are interposed between an output shaft of an engine and a load drive shaft. An automatic transmission (3) for shifting gears, a hydraulic circuit for selectively supplying hydraulic pressure to brakes and clutches of the automatic transmission (3) and selectively removing hydraulic pressure therefrom (second hydraulic circuit)
), An accumulator connected to the brake and clutch of the automatic transmission (3) in the hydraulic circuit (FIG. 2),
A pressure control valve (SL) for adjusting the back pressure of the accumulator
6), and, the absence shift principal determined comprises a shift control means (130) for performing transmission when the transmission is needed, the hydraulic control device for an automatic transmission: the brake (B ₂₎ which engages the first gear A timing control valve (SL5) that is turned on / off by electric bias for switching only a given hydraulic pressure between a high pressure and a low pressure; a modulator valve (90) that applies a high pressure regulated to the timing control valve (SL5); The timing control valve (SL5) is electrically energized on / off to determine that the shift control means (130) starts shifting to the first speed and provides a low pressure until the shift is completed. After that, a timing control means (130) for determining a high pressure is provided.

Symbols in parentheses indicate corresponding elements or items in the embodiment shown in the drawings and described later.

(Operation 1) In the shift to the first speed at which the maximum torque is transmitted, the timing control valve (SL) is used until the shift to the first speed is completed.
According to 5), a low pressure is applied to the brake (B ₂ ) to be engaged in the first speed, so that no discoloration shock to the first speed occurs. First
When the shift to the first speed is completed, the timing control valve (SL5) applies a high pressure for transmitting the maximum torque to the brake (B ₂ ) engaged in the first speed, so that the maximum torque transmission characteristic of the first speed is established. You.

(Means for Solving the Problems 2) A second invention of the present application is directed to a second aspect of the invention in which at least the first, second and third gear ratios are interposed between the output shaft of the engine and the load drive shaft. Automatic transmission (3) for shifting gears, in a first position for setting the gear ratio of the automatic transmission (3) in a low speed range including the first speed, and in a high speed range including the second and third speeds A manual valve (200) having at least two positions for defining and selectively supplying and removing hydraulic pressure from the brakes and clutches of the automatic transmission (3). A hydraulic circuit (FIG. 2), an accumulator in the hydraulic circuit (FIG. 2) connected to the brake and clutch of the automatic transmission (3), a pressure control valve (SL6) for adjusting the back pressure of the accumulator, and Determines whether or not a shift is necessary, and performs a shift when a shift is required A shift control means (130), a hydraulic control apparatus for an automatic transmission, comprising: a position detection means (134) for detecting the position of the manual valve (200); and a brake (B ₂ ) engaged in the first speed. A timing control valve (SL5) that is turned on / off by electric bias for switching only a given hydraulic pressure between a high pressure and a low pressure; a modulator valve (90) that applies a high pressure regulated to the timing control valve (SL5); The second position (D, S) detected by the position detecting means (134)
In response to the switching from the first position (L) to the first position (L), and after a predetermined time (T20a = 2 seconds), the timing control valve (SL5)
Timing control means (130) for updating the on / off of the switch to a switch that provides a high voltage (on).

(Function 2) When the range is switched from the D or S range to the L range, the hydraulic pressure is not immediately switched to the high pressure for transmitting the maximum torque but is performed after a predetermined time (T20a = 2 seconds), so that no switching shock occurs.

In addition, since such pressure adjustment is performed by the timing control valve (SL5) that is electrically biased, the timing control valve (SL5) is used when a predetermined time has elapsed accurately.
Are accurately switched, and the time until this switching is not affected by fluctuations in oil temperature, load, and the like.

Since the time until the switching is accurate as described above, there is no shock due to the time lag.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

(Embodiment) FIG. 1 shows an outline of a mechanism of an embodiment of the present invention. First
The automatic transmission shown in the figure includes a torque converter 1 having a direct coupling clutch 50, a subtransmission 2 composed of an overdrive mechanism, and a main transmission 3 composed of a gear transmission mechanism having three forward stages and one reverse stage. It is a combination.

The torque converter 1 is a known one including a pump 5, a turbine 6, and a stator 7. The pump 5 is connected to an engine crankshaft 8 and the turbine 6 is connected to a turbine shaft 9. The turbine shaft 9 serves as an output shaft of the torque converter 1, and serves as an input shaft of the auxiliary transmission 2.
It is connected to the carrier 10 of the planetary gear set in the subtransmission 2.

A direct coupling clutch 50 is provided between the engine crankshaft 8 and the turbine shaft 9, and when the direct coupling clutch 50 is activated, the engine crankshaft 8 and the turbine shaft 9 are mechanically coupled (lock-up).

The planetary pinion 14 rotatably supported by the carrier 10 meshes with the sun gear 11 and the ring gear 15.

Between sun gear 11 and carrier 10 are overdriven multi-plate clutch C ₀ and has overdrive one-way clutch F ₀ is provided, further between the housing or overdrive casing includes sun gear 11 and the overdrive mechanism overdrive multi-disc brake B ₀ is provided.

The ring gear 15 of the subtransmission 2 is an input shaft of the main transmission mechanism 3.
Connected to 23. Between the input shaft 23 and the intermediate shaft 29 and the front multi-plate clutch C ₁ is provided also between the input shaft 23 and the sun gear shaft 30 multiple disc clutch C ₂ is provided for the reverse. Between the sun gear shaft 30 and the transmitter Chillon case provided multiple disc brake B _1, sun gear 32 is carrier 33 provided in the sun gear shaft 30, planetary pinions 34 carried by said carrier, said pinion meshing Tsu ring The gear 35, another carrier 36, a planetary pinion 37 carried by the carrier, and a ring gear 38 meshing with the pinion constitute a two-row planetary gear mechanism. Between the carrier 36 and transmission case the one-way clutch F ₁ and the brake B ₂ is inserted. The ring gear 35 in one planetary gear mechanism is connected to the intermediate shaft 29. The carrier 33 in this planetary gear mechanism
Is connected to a ring gear 38 of the other planetary gear mechanism, and the carrier and the ring gear are connected to an output shaft 39. In such a fluid automatic transmission with an overdrive device, engagement or release of each clutch and brake is performed by a hydraulic control device described later according to the output of the engine and the speed of the vehicle, and includes overdrive (O / D). The shift of four forward speeds (first speed, second speed, third speed, fourth speed: O / D) and one shift forward speed (1.5th speed = LS) and one reverse speed by manual switching are performed. Has become.

Clutches C ₀ , C ₁ , C ₂ and brake for the above automatic transmission
FIG. 2 shows a hydraulic circuit for selectively operating B ₀ , B ₁ , B ₂ and the direct connection clutch 50 of the torque converter 1 to perform an automatic shift operation.

The hydraulic circuit shown in FIG.
1, pressure regulating valve 102, auxiliary pressure regulating valve 103, linear solenoid
SL6, manual valve 200, 1-2 shift valve 220, 2-3 shift valve
230,3-4 shift valve 240,1 / 2 solenoid valve for shift control SL1,2 / 3 solenoid valve for shift control SL2,3 / 4 shift solenoid valve for shift control SL3, accumulator 260,270,28
0,290, accumulator pressure control valve 110, modulator valve 90,
Orifice control valve 80, timing solenoid valve SL5, low coast modulator valve 250, exhaust pressure valve 70, lockup control valve 360, lockup control signal valve 370,
It comprises a solenoid valve SL4 for lock-up control, and other hydraulic elements and oil passages for servo communication between these valves and the hydraulic pressure of the clutch and brake.

The hydraulic oil pumped from the oil reservoir 100 by the hydraulic pump 101 is adjusted to a predetermined oil pressure (line pressure) by the pressure adjusting valve 102 and supplied to the oil passage 104 and the oil passage 105. The pressure oil supplied to the auxiliary pressure regulating valve 103 via the oil passage 105 is regulated by the linear solenoid valve SL6 to predetermined torque converter pressure, osmotic pressure, and cooler pressure according to the throttle opening and the vehicle speed. The manual valve 200 communicated with the oil passage 104 is connected to a shift lever provided in the driver's seat, and is manually operated to position P, R, N, D, S, and L according to the range of the shift lever. Moved to

As shown in FIG. 3, the hydraulic circuit shown in FIG. 2 uses the combination of energization (（) / non-energization (×) of the solenoid valves SL1 to SL3 for shift control, as shown in FIG. Determine the speed gear (numbers in the D, S, L columns).

In FIG. 3, O / D is the fourth speed (overdrive), and LS is the first speed (gear ratio 2.905) and the second speed (gear ratio 1.5).
30) is the middle speed stage (1.5th speed: gear ratio 2.257).

Here, the features of the above-described automatic transmission mechanism (FIGS. 1 and 2) will be described.
There is LS (1.5th speed). This LS (1.5th speed)
Is a relatively unstable traveling state in which the speed is slow at the first speed and the power is insufficient at the second speed in the climbing road traveling when the weight of the vehicle is heavy (the shift between the first speed and the second speed is relatively frequent). In this state, the shift between the first speed and the second speed is likely to cause a shift shock), and also, a running state where the engine brake is too heavy at the first speed and the braking is bad at the second speed during the downhill traveling (No. Even if the shift between the first speed and the second speed is relatively frequent and the shift between the first speed and the second speed in this state is likely to cause a shift shock, the speed is relatively fast and sufficient on the uphill road. It is designed to realize a smooth running characteristic in which power can be obtained, and to realize a smooth running characteristic in which an appropriate engine brake can be obtained in downhill running.

Assuming that the first range is between D1 and D2,
When the 5th speed (LS) is set automatically, the speed range included in the 1st speed and 2nd speed of the D range changes from 2 divisions to 3 divisions, and the speed range of each speed stage becomes narrower, The frequency increases, and the driver's sense of strangeness due to speed change due to the shift shock or the change of the speed stage increases.

Therefore, in this embodiment, the 1.5th speed (LS) is set in response to the designation of the 1.5th speed (LS) by the driver operating the switch when the position of the shift lever is in the L range.

In the automatic transmission mechanism shown in FIG. 1, the sub-transmission 2 is overdriven (O / D; _{C0 is} disconnected, _{B0 is} released) and the main transmission 3 is in the first speed (C
_{If the} gear ratio is ₁ contact, C ₂ disconnection, B ₁ release, B ₂ engagement), then the gear ratio is the intermediate value (2.50 and 1.530) between the first gear ratio and the second gear ratio (2.950 and 1.530).
257), which is defined as the 1.5th speed (LS),
When the speed is designated, the sub-transmission 2 is set to O / D and the main transmission 3 is set to the first speed (FIG. 3).

The second feature of the automatic transmission mechanism shown in FIG. 1 and FIG.
Are accumulators 260 and 27 to prevent shifting shock.
0, 280 and 290, the back pressure of the piston (pressed upward by a compression coil spring not shown) is controlled by a linear solenoid valve SL6 via an accumulator pressure control valve 110, and by a timing solenoid valve SL5. , the brake B ₁ via both the orifice 81 and the orifice 82 (slow rising), or orifice 82 (fast rising) bypass to be controlled supplies pressure oil, loading / release of the clutches and brakes The switching of those pressures at the time of switching is smooth.

In this embodiment, the output pressure of the linear solenoid valve SL6 (the actuator pressure control valve 110 applies a pressure proportional thereto to the accumulators 260 to 290) is substantially inversely proportional to the energization duty of the valve SL6. That is, the linear solenoid valve
When the energization duty (current value) of SL6 increases, the piston back pressure of accumulators 260 to 290 decreases, and the hydraulic pressure applied to the above-described clutches, brakes, and the like decreases. In the shift mode in which shift shock is likely to occur, the current value (energization duty) of the linear solenoid valve SL6 is set high so as not to cause shift shock.

Turn on the timing solenoid valve SL5 (duty 100%
When this occurs, the pilot pressure chamber of the orifice control valve 80 is connected to the drain, so that the orifice control valve 80 brakes the oil path connecting the orifices 81 and 82 B ₁
Bypass to (accumulator 280). Thus the faster the pressure drop rate is high brake release speed when releasing the brake B ₁ (fast engagement speed when the brake engagement). However, when the timing solenoid valve SL5 is turned off (duty 0%: no power is supplied), the hydraulic pressure in the pilot pressure chamber of the orifice control valve 80 increases, and the orifice control valve 80 is connected to the oil passage connecting the orifices 81 and 82 with the brake B ₁
(Accumulator 280). Since this the brake B ₁ represents is connected to the hydraulic line through the orifice 81 and 82, the pressure drop is slow if when releasing the brake B ₁ (brake release speed is slow),
In the case of engaging the brake B ₁ and the pressure increase rate is low (brake engagement speed is slow).

FIG. 4 shows an outline of an electric control system for controlling energization of the shift solenoid valves SL1 to SL3, the lock-up control solenoid valve SL4, the timing control solenoid valve SL5, and the linear solenoid valve SL6 of the hydraulic circuit shown in FIG.

The main part of the electric control system is a control board 130, which is a combination of a microcomputer (hereinafter referred to as a CPU) and an input / output interface on a printed circuit board. The input interface of the control board 130 includes a pulse generator 140 that generates an electric pulse having a frequency proportional to the rotation speed Ne of the input shaft (output shaft of the engine) 8 of the torque converter 1 and an output shaft (C A pulse generator 141 for generating an electric pulse having a frequency proportional to the rotation speed Nt of _one drum 23, and an electric pulse having a frequency proportional to the rotation speed No of the output shaft (wheel drive shaft) 39 of the main transmission 3 A pulse generator 142, a first speed (LS) instruction switch 131, a fuel saving travel instruction switch 132, a fourth speed (O / D) inhibition instruction switch 133,
A shift lever position detection switch 134, a water temperature sensor 135 for detecting the temperature of the engine coolant, an oil temperature sensor 136 for detecting the temperature of the oil in the oil reservoir 100 of the hydraulic circuit shown in FIG.
The brake switch 137, the throttle opening sensor 138, the idling opening sensor 139, the ignition key switch IGS, and the batteries 163 and 164 on the vehicle are connected.

An indicator lamp is connected to the various input switches described above. When the first speed instruction switch 131 is closed (first speed instruction), the lamp 152 is turned on, and the fuel saving travel instruction switch 1 is turned on.
When 132 is closed (saving driving instruction), the lamp 132 lights up,
When the fourth speed (O / D) prohibition switch 133 is closed (prohibition instruction), the lamp 154 is turned on.

When the shift lever position is N (neutral), the switch 134 is in the D position and the lamp 155 is lit,
At the time of R (back), the lamp 156 is turned on, and at the time of P (parking), the lamp 157 is turned on. When the shift lever position is L, the switch 134 is in the L position, and the lamps 158 and 161 are turned on. When the shift lever position is S, the lamps 159 and 161 are turned on. When the shift lever position is D, the lamps 160 and 161 are turned on. Lighting of the lamp 161 means that the shift lever position is at the forward position.

When the brake switch 137 is closed (the brake pedal is depressed), the lamp 162 is turned on.

The electric pulses generated by the pulse generators 140, 141 and 142 are shaped into rectangular waves of a predetermined level by the input interface, and applied to the external interrupt input port of the CPU of the control board 130. Signals of binary switches such as a first speed instruction switch 131 and a shift lever position detection switch 134 (open:
High level H = unspecified; closed: low level L = specified)
In the input interface, the chattering at the time of the level switching at the input interface is eliminated, the signal is shaped into a single rising or falling, and is applied to the input port of the CPU of the control board 130.
The analog signals of the water temperature sensor 135, the oil temperature sensor 136, and the throttle valve opening sensor 136 are subjected to smoothing and amplification for level calibration at an input interface, and are then input to an analog signal input port (A / A) of the CPU of the control board 130. D conversion input port).

CPU of the control board 130 detects the standing by executing an interrupt processing for each downlink engine rotational speed Ne, the rotational speed N ₀ of the rotational speed Nt and the wheel drive shaft of the auxiliary transmission output shaft of the generated pulses of the pulse generator 140, 141, 142 Then, the open / closed states of the various input switches and the detection switches (the presence or absence of various instructions) are read, and the water temperature signal, the oil temperature signal, and the throttle valve opening signal are converted into digital signals and read, and the speed stage shown in FIG. 3 is set. , Speed change (shift = conversion), transmission abnormality detection, water temperature abnormality detection, oil temperature abnormality detection, etc. When an abnormality is detected, the abnormality display lamp 151 lights up in a blinking pattern corresponding to the abnormality. Energize.

The CPU of the control board 130 performs the setting of the speed stage (FIG. 3) and the switching of the speed stage, and the switching of the pressure of the clutch and the brake and the adjustment of the pressure at the time of lock-up / release, via an output interface. energization of the solenoid valve SL1～3 (on) / switching-energized (oFF), oN / oFF switching or current duty control of the solenoid valves SL4,5, and linear solenoid corresponding to the throttle valve opening θ and the vehicle speed N ₀ This is performed by controlling the current value of the valve SL6 (controlling the energization duty).

When the ignition key switch IGS is open, the control board 130 includes a memory backup power supply circuit that constantly supplies a voltage for holding the memory to the CPU even when the ignition key switch IGS is open.When the ignition key switch IGS is open, the CPU Holds data written to internal memory. The input switches, lamps, and various sensors are connected to a signal processing circuit that receives power from a signal processing power supply circuit that is supplied with power from the batteries 163 and 164 via an ignition key switch IGS, and the solenoid valves SL1 to SL6 are connected to the ignition key switch IGS. And connected to an output terminal of a solenoid driver that receives power from a high power power supply circuit supplied with power from the batteries 163 and 164 via the power supply circuit. A predetermined voltage is applied to the control signal input circuit of the solenoid driver from the signal processing power supply circuit. Therefore, the ignition key switch
While IGS is open, the memory backup power supply circuit and CPU
Only consume very little power (battery power).

FIGS. 5a, 5b, 5c, 5d and 5e show an outline of the control operation of the CPU of the control board 130 (outline of the main routine).

Power is supplied to the control board 130 (the battery 163 is connected to the control board 130; step 1: FIG. 1; hereinafter, steps and subroutines are omitted in parentheses, and only numerals attached thereto are described) The CPU sets the internal registers, timer, counter, and the like to an initial standby state, and outputs a standby signal level to an output port (2). Thus, SL1 to SL6 are all turned off (non-energized).

The battery 164 is also connected as shown in FIG. 4, and when the ignition key switch IGS is closed thereafter, the CPU while closed is controlled by the control (1) in steps 3 to 69 in FIGS. 5a to 5e. Cycle control) is repeated in the TP cycle.

At the beginning of one-cycle control, the timer TP is started (3). Next, signals from the above-described input switch, throttle valve opening sensor and the like are read (4). Then, in the data processing 1 (5), the read input is written into a register referred to in the execution of the control program, abnormality determination of each unit is performed based on the input data, and when an abnormality is detected, the lamp 151 is turned on.

Next, the CPU of the control board 130 performs data processing 2 (6).
Corresponding to the shift lever position, the speed stage (current speed stage) currently set in the automatic transmission (FIG. 1), and whether or not the fuel-saving travel instruction switch 132 indicates fuel-saving travel, From the current speed stage (the contents of the current speed stage register PS), the next speed stage (possible shift mode) which can be shifted up / down is determined. In this embodiment, from each speed stage (for example, third speed) to other speed stages (first speed, second speed).
Speed (fourth speed) (shift = shift), a reference vehicle speed value (reference vehicle speed value group) using the throttle valve opening as a parameter is referred to when fuel-saving driving is designated. Things to Do (Economy Mode Data Group: Chapter 15
b) and the data to be referred to when it is not specified (power mode data group: FIG. 15a). Therefore, in the data processing 2 (6) described above, the shift mode that can be performed at the current speed stage is used. And data indicating whether the vehicle is in the economy mode or not. The data for designating the reference vehicle speed value group is determined.

Next, the CPU of the control board 130 reads the above input (4).
The shift lever position (output of the switch 134) and the 1.5th speed (LS) designation (switch 13)
It is checked whether or not the 1.5th speed (LS) should be set (7, 11) based on the correlation with (1 opening and closing). In this embodiment, the 1.5th speed is set only when the two conditions of the shift lever position being L and the switch 131 being closed (1.5th speed instruction) are satisfied. If this is the case, 1 (1.5th speed setting required) is written to the register LSF (12). If this is not the case, the register LSF is cleared (13).

In the next shift determination (14), the content of the register LSF is set to 1 (1.5th) with reference to the current speed stage (the content of the current speed stage register PS), the content of the register LSF and the input data of the fourth speed inhibition switch 133. In the case of (speed setting required), data indicating the 1.5th speed is written in the target speed stage register DS. When the content of the register LSF is 0 (the 1.5th speed is not specified), the data indicating the shift mode that can be set at the current speed stage set in the data processing 2 (6) and the economy mode are indicated. First, based on the data for designating the reference vehicle speed value group, a speed stage capable of shifting up from the current speed stage (contents of the register PS) (excluding the fourth speed if the prohibition switch 133 is closed) ), The reference vehicle speed value group (one of the solid curves shown in FIGS. 15a and 15b) is specified from the higher speed stage (SRi speed), and the current throttle valve opening degree is determined from this data group. If it is the corresponding reference speed value (specified value of a point on the solid line curve) selected which vehicle speed N ₀ is equal to or greater than the reference vehicle speed values compared to the current vehicle speed N ₀ (the shift-up required) that the SRi The speed data is written to the target speed stage register DS. If the speed is lower than the vehicle speed value, this writing is not performed and the same determination is made for the next lower speed stage. If it is not necessary to upshift any of the speed stages higher than the current speed stage, then, from the lower speed stage (the SRj speed) among the speed stages that can be shifted down from the current speed stage, the reference A vehicle speed value group (one of the dashed curves shown in FIGS. 15a and 15b) is specified, and a reference speed value (a value of one point on the specified dashed curve) corresponding to the current throttle valve opening is determined from this data group. ) Is compared with the current vehicle speed N _0, and if the vehicle speed N ₀ is lower than or equal to the reference vehicle speed value (shift down is required), data indicating the SRth speed is written to the target speed gear register DS. If the vehicle speed value is exceeded, the same determination is made for the next higher speed stage without writing. Switch 13
When 3 is closed (fourth speed prohibited) and the content of the current speed stage register PS is the fourth speed, the target speed stage register DS is used to shift down from the fourth speed to the third speed. Third
Write speed.

Next, the CPU of the control board 130 compares the current speed stage (the content of the register PS) with the content of the target speed stage register DS (the speed stage to be set).
If the gear is not currently shifting, the speed stage of the target speed stage register DS is written to the next speed stage register SS and the next speed stage register SSN (15-16-17-18). If the gear is currently being shifted, the speed stage of the target speed stage register DS is written only to the speed stage register SSN one after another (15-16-17-36).

Next, if the gear is not currently shifting, the timer TB for the TB time is started (19), and 1 is set in the register TBF (the timer TB is operating).
Is written (20). When the timer TB times out, the solenoid valves SL1 to SL3 and the timing solenoid valve SL5
Is set to an energized state for setting the speed stage written in the next speed stage register SS, and a timer required for timing control for smooth switching of clutch and brake oil pressure during shifting is started. Set data in various registers (44-54).

Then, detection of the shift time (TSO, TSE) (64), control of the linear solenoid valve SL6 (65), and timing solenoid valve S
L5 control (65), lock-up control (67), and output control (68) are executed in this order, and wait for the timer TP to expire (69), and start the timer TP (3) , The control operation of the next one cycle is started. By repeating the TP cycle of the control operation of this one cycle, the shift determination and the shift up / down control when the shift is necessary are performed.
Realized smoothly in time series.

6a and 6b show the details of the detection (64) of the shift time (TSO, TSE) shown in FIG. 5d, FIG. 7 shows the details of the linear solenoid SL6 control (65) shown in FIG. 5d, and The contents of the timing solenoid SL5 control (67) shown in FIG. 5d are shown in FIGS. 8a and 8b.

 The meanings of the various symbols in these drawings are as follows.

LSF: Register for storing information on the presence / absence of 1.5th speed designation. The content "1" indicates that the 1.5th speed is specified, and "0" indicates that the 1.5th speed is not specified.

PS: Current speed gear register. The content of the automatic transmission (No. 1
The current speed stage (parking P, back R, neutral N, first speed, 1.5th speed, 2nd speed, 3rd speed or 4th speed) of FIG.

DS: a register for temporarily storing the speed stage (first speed, 1.5th speed, 2nd speed, 3rd speed or 4th speed) determined to be set next by the shift determination.

SS: Next speed stage register. A register for storing the speed stage (first speed, 1.5th speed, 2nd speed, 3rd speed or 4th speed) to be set. The gearshift mode is determined by the contents of PS and SS.

SSN: Next to speed stage register. A register that stores the speed steps that must be set (shifted) continuously after shifting from PS to SS.

TBF: Flag register for indicating whether or not timer TB is operating. 1 of the contents is in operation, 0 is not in operation (timer TB
Has not started).

TEF: Flag register for indicating whether or not the timer TE is operating. 1 of the contents is operating, 0 is not operating (timer TE
Has not started).

PUF: Flag register indicating whether or not a power-on upshift. The content 1 means shift-up (shifting to a higher speed stage) in a state in which a load for vehicle propulsion is applied to the engine (power-on), and 0 means shift-down (lower speed stage). Shift) or an upshift in a state where no vehicle propulsion load is applied to the engine (power off: inertial running or engine brake running).

TEIF: Flag register indicating the start point of the shift period. The content 1 means immediately after the start of the timer TE.

TEFF: A flag register indicating immediately after the end of the shift period. One of the contents is that the timer T2D
Is the period until the time expires.

i, j: Count registers. The number of times of detection as to whether the power is on (the engine is subjected to a vehicle propulsion load) or not (power off) is written.

k: count register. Nt1> Nt2 (Nt2:
This time Nt, Nt1: The number of times Nt before TP is satisfied is stored.

TTF: A flag register indicating the end of the shift time measurement. 1 of the content means that the measurement of the shift time TT has been completed,
0 means that the shift time detection has not been completed.

TCR: a flag register indicating an abnormality in the shift time TT. One of the contents means that the shift time is abnormal.

CR: A register for writing data indicating the appropriateness of the shift time TT.

POI: Flag register indicating whether or not it is necessary to set the initial value of the energization duty of the linear solenoid SL6. The content 1 means that the initial value setting has been completed.

ADMEM: A register that stores the energization duty learning value of the linear solenoid valve SL6.

ADIN: Register that stores the energization duty value (computed value) that energizes the linear solenoid valve SL6.

ATIN: A register that stores the energization duty value (computed value) that energizes the timing solenoid valve SL5.

 Next, the contents of the control operation of this embodiment will be described.

(1) Detection of Ne, Nt, and No.

The CPU of the control board 130 is an ignition key switch IG
Immediately after S is closed, three (timers 1 to 3) timers (program timers) for a predetermined time period are started, and interrupt processing in response to the generated pulses of the pulse generators 140, 141, 142 is permitted. Then, for example, when the falling of the pulse generated by the pulse generator 140 arrives, the process proceeds to the interrupt processing, and first, the content of the count register 1 is incremented by one, and then it is checked whether or not the timer 1 has timed out. If the time has not elapsed, the control returns to the control before proceeding to the interrupt processing. If the time is over, the contents of the count register 1 are written to the speed Ne calculation register Nef, the timer 1 is restarted, and the control returns to the previous one. When the falling edge of the pulse generated by the pulse generator 141 arrives, the process proceeds to an interrupt process, where the content of the count register 2 is first incremented by one, and then
Check if timer 2 has timed out,
If the time has not elapsed, the control returns to the control before proceeding to the interrupt processing. If time is over, count register 2
Is written into the register Ntf for calculating the speed Nt, the timer 2 is restarted, and the process returns to the previous control. Pulse generator 14
When the falling of the generated pulse 2 arrives, the process proceeds to the interrupt processing, and first, the content of the count register 3 is incremented by one,
Next, it is checked whether or not the time of the timer 3 has expired. If the time has not elapsed, the process returns to the control before proceeding to the interrupt processing. If the time is over, the contents of the count register 3 are written into the speed N ₀ calculation register N ₀ f, the timer 3 is restarted, and the control returns to the previous control.

By executing these interrupt processes, the pulse generators 140 and 14 are stored in the speed calculation registers Nef, Ntf and N ₀ f, respectively.
The number of pulses generated during the last predetermined time period of 1 and 142 will be written. In the data processing 2 (6) of FIG. 5a, the CPU of the control board 130 obtains the speeds Ne, Nt and Nf from the data of the speed calculation registers Nef, Ntf and N ₀ f (the number of pulses generated within a predetermined time period). Calculate N ₀ and set the speed register N
e, written in the speed register Nt and the speed register N _0. As a result, the latest speed data always exists in these speed registers.

(2) Outline of control timing from when it is determined that a shift is necessary to when the shift is completed.

In the case of an upshift, as shown in FIG. 9a, it is determined that a shift is necessary (white triangle) in the shift determination (14, 15), and then the timer TB is started (19). The energization of SL1 to SL3 is switched to a state for setting the next speed stage (43 to 48). This is the timing of “shift output” indicated by the black triangle in FIG. 9a. For example, in the case of a 2 → 3 shift, the energization / non-energization of the solenoids SL1 to SL3 is set to the energization / non-energization state of the row indicated by “3” in the column D shown in FIG. Then, start the timer TE (4
6).

In this embodiment, TB = 0.2 sec, but TE is
It is set to 0.8 sec for 4 → 3 downshift, and set to 1.5 sec for other up and downshifts. These TE values are the time TSO from when the shift output (48) is output until the mechanical switching actually starts, and the time between when the mechanical switching starts and when the mechanical switching is completely completed. TT (mechanical shift time: this is the actual shift time) is set to a value larger than the sum TSE.

(3) Measurement of the mechanical shift time TT.

The mechanical shift time TT fluctuates due to the wear state of the friction member of the automatic transmission (FIG. 1), the vehicle running load, and the like. If the mechanical shift time TT is too small, a shift shock is likely to occur. And disadvantages such as poor acceleration are provided, and serve as a guide for determining the quality of the automatic transmission.

In this embodiment, in the 1 → 2 or 2 → 3 upshift, the mechanical shift time TT is measured after the timer TE is started. This is shown in Figure 6a. In this case, when a decrease in the speed Nt is detected two or more times consecutively in the TP cycle, the mechanical switching is started and the timing of the mechanical shift time TT is started (81 to 87). ,
When the current Nt value drops below 2.5 rpm from the previous Nt value, the mechanical switching is completed and the timing of TT is stopped, and the time value TT is written to the register TT (88 to 90). , TT
1 is set in the flag register TTF to indicate that
Is written (91).

(4) Detection of transmission failure based on the mechanical shift time TT. Abnormal vehicle running or transmission mechanism, such as abnormally high vehicle running load, excessive wear of friction members such as clutches and brakes of the automatic transmission (FIG. 1), or occurrence of some abnormality in the transmission mechanism. In the case of a failure or an abnormality, the mechanical shift time TT becomes too long or too small, and there is a high possibility that a shift shock or engine blowing will occur. Therefore, in this embodiment, as shown in FIG. 10d, eight areas of up to 8 are defined around the basic shift time (fixed value) TS using the throttle valve opening θ as a parameter, and the measured shift time TT Check if it is in the area (92 in Fig. 6b)
If it is in the area or, 1 is written to the abnormality register TCR (103), and an abnormality display (lighting energization of the lamp 151) is performed (104). If the number is An, the count An is counted up. If the count An is less than 4, 2 is written to the suitability register CR (99 to 102). 4 times
At this point, the same processing as in the above-described area or is performed. If it is the area or, the abnormality is cleared (96, 97), and 1 is written to the appropriateness degree register CR (98). Clear the error in the area or at (9
3,94), write 0 to the propriety degree register CR (register CR
Clear: 95). Therefore, the data in the registers CR and TCR indicate the appropriateness of the shift time.

(5) Multiple shifts.

The period (TB
+ Between TE), when there is a change in the change and the vehicle speed N ₀ of the throttle valve opening, the speed stage to be updated with the period (TB + TE) it may become shifting essential to speed stage has different Tsu.

If it is determined that shifting is required during the TB period (from the start of the timer TB to the time when it expires), the next speed stage that has been required to be set is written to the next speed stage register SS (see FIG. 5b). twenty three). This allows the register to be
Since the speed stage written in SS disappears by this writing,
The speed stage switching output (48 in FIG. 5c) when the timer TB times out sets the speed stage determined during the TB period.

If it is determined that a shift is necessary during the shift period after the TB period (during the timer TE operation, that is, TEF = 1) (15-16-17), the immediately preceding shift change has already been completed. The speed stage to be set next is written into the speed stage register SSN (36), and when the timer TE expires, a switching output to the speed stage newly determined to be necessary for shifting is performed subsequently (41-42-55-56-). 57-58-44 to 48). That is,
The speed stage is switched immediately following the previous TE without setting a TB period again.

(6) Power-on upshift determination.

In a power-on upshift, a shift shock is likely to occur during a gear shift (TE), and in a power-off upshift, an engine is easily blown up. Therefore, the upshift (T
E) In some cases, the hydraulic pressure switching speed is determined in accordance with the power on / off to prevent a shift shock and an engine blow-up. For this purpose, detection of power on / off is required. This detection is based on the fact that the throttle valve opening θ, the vehicle speed N ₀ , the engine speed Ne, and the speed Nt of the output shaft of the auxiliary transmission 2 change every moment. Therefore, it is preferable to detect immediately before the shift (TE). Therefore, in this embodiment, power on / off detection is performed during the TB period (16-23 to 35). The power-off determination is also made during the TE period (17-36-32 to 3
Five).

That is, during the TB period (TBF = 1) when the shift mode is an upshift, if Ne ≧ Nt is satisfied, the number register i
Is incremented by one (16−23−24−27−28−2).
9) When the content of the number-of-times register i becomes 2 or more, 1 indicating a power-on upshift is set in the flag register PU.
Write to F (31). Ne <N during TB or TE period
At time t, the content of the count register j is incremented by 1 (32, 33), and when the content of the count register j becomes 2 or more, the flag register PUF is cleared (35). A 0 by clear means that the power is off. In this way, if the shift mode is upshift, the timer TB
It is continuously determined whether the power is on or off until the timer times out. After the timer TB has expired, it is determined whether the power is off. When the power is determined to be on, the PUF content is set to 1 and the power is turned off. Is determined, the content of the PUF is set to 0. Therefore, when the shift output (48) is performed, information indicating whether or not the power is on at that time is in the register PUF.

(7) Steady-state control of the energization duty of the linear solenoid SL6 (FIG. 7).

The linear solenoid SL6 generates a hydraulic pressure that is substantially proportional to the current flowing through the electric coil, and the accumulator pressure control valve 110 supplies the hydraulic pressure that is proportional to the hydraulic pressure to the accumulator 260.
Give ~ 290 to piston back pressure. FIG. 9b shows the relationship between the energizing current value of the linear solenoid SL6 and the piston back pressure of the accumulators 260 to 290. In this embodiment, the energizing current value of the linear solenoid SL6 is determined by the energizing duty. The relationship between the energization duty and the energization current value (average current value due to repetition of energization / de-energization) is as shown in FIG. 9b.

The linear solenoid SL6 mechanically interlocks with the conventional rotary shaft of the throttle valve and adjusts the line pressure to a value corresponding to the throttle valve opening and the governor pressure in response to the governor pressure corresponding to the engine speed. It is used in place of a conventional throttle valve of a conventional hydraulic circuit. The CPU of the control board 130 controls the back pressure of the accumulators 260 to 290 to prevent the shift shock at a specific timing (mainly during the TE period) of the specific shift mode, and performs the following (8) back pressure control. 9c, the current value shown in FIG. 9c (the energizing duty corresponding to this) corresponds to the throttle valve opening θ and the rotation speed Nt of the output shaft of the auxiliary transmission 2 in other cases. Is turned on. That is, the throttle valve opening θ and the rotation speed
Accumulators 260 to 290 and 2 corresponding to Nt
→ It is given to the 3-shift valve 60 (115, 116 in FIG. 7).

(8) Back pressure control of the accumulator during shifting (FIG. 7).

1 → 2, 2 → 3 or 3 → 4 power-on upshift (P
When UF = 1), in order to prevent a shift shock, during the shift period (TE: see FIG. 9a), the linear solenoid S
First, the energization duty of L6 (the piston back pressure of the accumulators 260 to 290) is roughly determined by K1 × K2 × [K3 (1-TT / TS) + ADMEM].

K1 is an environmental change correction coefficient, and K1 = K11 + K12, K11:
Oil temperature correction coefficient, K12: correction coefficient corresponding to throttle valve opening. K2 is a correction coefficient corresponding to the shift mode and the throttle valve opening, and K3 is a correction coefficient corresponding to the shift mode. The values of these correction coefficients are shown in Figs. 10a and 10b, respectively.
Figures 10c and 10d are shown. K11 is oil temperature sensor 1
It is calculated corresponding to the detected temperature of 36 (118 in FIG. 7). K12
Is calculated corresponding to the throttle valve opening θ (11
8). K2 is calculated according to the throttle valve opening θ and the shift mode (120). Since K3 is a value associated with the shift mode on a one-to-one basis, a value corresponding to the shift mode (the contents of the registers PS and SS) is selected.

TT is the latest mechanical shift time TT (data detected in the flow of FIG. 6a and stored in the register TT), and TS is the basic shift time (fixed value). ADMEM is an energization duty value determined by the learning correction so far.

The CPU of the control board 130 calculates the above K1 × K2 × [K3 (1-TT / TS) + ADMEM] as follows. First, the learning value so far
ADMEM (contents of register ADMEM) to the latest mechanical shifting time
An appropriate value [K3 (1-TT
/ TS) + ADMEM] (learning correction) and register ADMEM
(126), and then the current environmental coefficient K1 (= K
11 + K12) and K2 are multiplied by the data of the register ADMEM, and this (that is, K1 × K2 × [K3 (1-TT / TS) + ADME
M]) is written into the output data register ADIN addressed to the linear solenoid SL6 as the output duty (128). In addition,
In the output control (68 in FIG. 5d), the CPU of the control board 130
Outputs an on (energized) / off (non-energized) signal of the duty indicated by the data in the output data register ADIN to the solenoid driver that energizes SL6.

The control of the automatic transmission (FIG. 1) is possible only when the power to the control board 130 is turned on when the batteries 163 and 164 are connected to the control board 130 and then the ignition key switch IGS is closed. When this becomes possible, there is no learning value ADMEM for the energization duty of the linear solenoid SL5. At this time, the content of the register POI is 0
It is. Therefore, when the content of POI is 0, register ADM
An initial value (fixed value) is written to EM, and 1 (initial value set) is written to POI (122, 123). At this time, since the learning value cannot be updated (126), this is not performed, and the value obtained by multiplying the environment-related coefficient by ADMEM at that time is determined as the energization duty (124).

By the way, as described in the above (4), when the transmission is defective, the shift time TT is a value shifted from the reference value TS.
6) becomes inappropriate. Therefore, referring to the suitability of the shift time TT (the contents of the registers TCR and CR), if the shift time TT is in the area or (FIG. 10d), the learning correction (126) is not performed and The energization duty value of the linear solenoid SL6 is determined by correcting the energization duty value (ADMEM) for the environmental change (125-128). That is, the learning correction of the energization duty value is performed only when the shift time TT is in the range 1 to. As a result, only when the shift characteristic (TT) of the automatic transmission is within an appropriate range, the automatic pressure adjustment (power supply duty correction) for bringing the shift time TT close to the appropriate value TS is smoothly performed in time series.

To the 11a Figure, 2 → 3 When shifting, shows the time series change of the brake B ₁ and the clutch C ₂ hydraulic. In this drawing, the oil pressure of the brake B ₁ is the one at the time of power-on with a solid line,
The power-off state is indicated by a broken line. Hydraulic clutch C ₂ is the thick solid line obtained when the power-on, indicated by the two-dot chain line and the chain line, is not shown that when the power-off.

Above, depending on the energization duty of the linear solenoid SL6 by accumulator back pressure control is performed only at power-on, it is low when the fast pressure rise of the clutch C _2, as shown by two-dot chain line, the shift time TT becomes shorter.
If the energization duty is high, the clutch
Shift time TT is prolonged pressure rising of C ₂ becomes slow.
Note that when the power-off, power supply duty at the time of gear shifting is 0 since it is on (off) the oil pressure of the rising of the clutch C ₂ is very fast, neutral period shown in the figure is shorter than shown.

As described above, the mechanical shift time TT corresponding to the energization duty becomes longer when it is higher, and becomes shorter when it is lower. In the above accumulator back pressure control, the previous energization duty value
+ K3 (TS-TT) / TS correction amount, ie, shift time reference value TS
And a correction value corresponding to the deviation amount of the actual gear shift time TT is added to the next energization duty value (126 in FIG. 7).
In other words, learning correction is performed, so that the mechanical shift time TT is equal to the reference value TS.
Converges to That is, the energization duty is automatically adjusted in response to a change in the engagement characteristics due to wear of the friction member of the brake (B ₁ ) and the clutch (C ₂ ), and the shift time of the reference value TS is substantially maintained. A shift shock due to a change in the engagement characteristics does not occur.

(9) Control of the timing solenoid SL5 at the time of shifting (No. 8a
Figure and Figure 8b).

The timing solenoid SL5 defines the falling speed of the hydraulic when the start-up rate and release of the brake B ₁ of the engagement of the brake B ₁ oil pressure. Since the brake B ₁ represents are engaged only by the second speed (see FIG. 3), shift shock is performed hydraulic pressure rise / fall speed control of the brake B ₁ in shift mode associated with the hydraulic brake B ₁ To prevent

In the case of the 2 → 3 shift shown in FIG. 11a, at the time of power-on, the timing solenoid SL5 is kept off (non-energized) continuously (131-132-135-145 in FIG. 8a).
-Return), whereby the bypass valve 80 closes the flow path bypassing the orifice 82. Thus the brake B ₁ represents, since the leads through the orifice 81 and 82 and the 2 → 3 shift valve 60 connecting it to the drain (low pressure), the brake B ₁ exhaust pressure (pressure vent) speed is low. Note that if the power is turned on (PUF = 1) to power off (PUF = 0) by the time 0.1 sec has elapsed from the start of the TE period, the CPU of the control board 130 will operate when the timer T1 times out. Then, turn on the timing solenoid SL5 (1
32-145 to 147: rising of a broken line after 0.1 sec in the column of SL5 in FIG. 11a). That is, data specifying the energization duty of 100% is written into the output register ATIN addressed to the timing solenoid SL5 (147). This time limit value T1 (0.1 sec) is 0.1 to
Other values in the range of 0.3 sec may be used. Since Turning on timing solenoid SL5 open a flow path bypass valve 80 to bypass the orifice 82 (to flowing state), the exhaust圧速of the brake B ₁ is increased. After the TE period,
Timing solenoid SL5 is off (energization duty 0
%) (131-149-156-157-159 in FIG. 5b).
The first 11a view, the pressure change of the brake B ₁ (power-on)
Is indicated by a solid line. The CPU of the control board 130 outputs (6
8: FIG. 5d), referring to the data of the output register ATIN addressed to the timing solenoid SL5, and transmitting the duty on (energization) / off (non-energization) signal indicated by the data to the solenoid driver connected to the solenoid SL5. And output.

When the power is off even in 2 → 3 shift, the control board
130 CPU enters the timing period, the timing solenoid SL5
Is turned on (energization with 100% energization duty) (134), TE
After the period, the power is turned off (the energization duty is 0%) ((131-149-156-157-159 in FIG. 5b)).

FIG. 11c shows the energizing timing of the timing solenoid SL5 when converting to the second speed upon power-on. When converting to the second speed, during a period A of 0.4 sec after the start of the TE period, the throttle valve opening θ and the rotation speed N ₀ of the output shaft of the main transmission 3 are set in the region shown in FIG. It is determined which of I to IV and the area not to be controlled (131-132-
135 to 139), when in the region I, the energization duty of the timing solenoid SL5 is set to 100% (ON) (14).
0), set to 65% when in area II (141), area II
Set to 50% when in I, 0 when in Region IV
% (Off) (142). FIG. 11d shows the division of the solid lines in the regions I to IV, and FIG. 11e shows the relationship between the determined region and the energization duty determined corresponding thereto. And
Period B after 0.4sec has elapsed and TE has not elapsed (Fig. 11c)
It is determined whether the throttle valve opening θ and the rotation speed N ₀ of the output shaft of the main transmission 3 are in the regions I to IV shown in FIG. 11b (accurately, FIG. 11d) or in the uncontrolled region. A determination is made, and the area step difference between the currently determined area As and the previously determined area Ap is checked (138). If there is more than two areas apart, the energization duty corresponding to the currently determined area As is determined (139- 140-143). When the area difference is 1 or less, the energization duty is not changed (133-144). The pressure change of the brake B ₁ by such energization duty control shown in 11f FIG.

In the case of power off up control, 2 → 3 or 2 → 4
At the time of shifting, the timing solenoid SL5 is turned on (energization duty 100%) (132-145-146-133-13).
Four).

In the case of the 2 → 1 shift, as shown in FIG. 11g, the timing solenoid SL5 is turned off (energization duty 0%) until the shift is completed (TE has elapsed), and the timing solenoid SL5 is turned on (energization duty 100%) with the end of the shift. I do. The more the brake B ₂ pressure, after TE (1.5 seconds),
The high hydraulic pressure for transmitting the maximum torque of the first speed is obtained. From shifting
The hydraulic pressure is switched to the first gear after TE, so immediately after shifting (TE
Inner) In the brake B ₂ oil pressure is low, no shift shock.

(10) Energization control of the timing solenoid SL5 when the shift lever position is switched from D or S to L (eighth
a figure).

When the shift lever position is switched from D or S to L, the CPU of the control board 130 writes 1 in the manual shift detection register and starts the timer T20a for the time period T20a (2 seconds) (131-149-150-151). Turns on the timing solenoid SL5 when the
%) And clear the manual shift detection register (131-149-150-152-153 to 155). Accordingly, the shift lever position is hydraulic pressure of the brake B ₂ therefrom when switched to L from D or S after T20a (2 seconds), it rises to the oil pressure for maximum torque transfer of the first speed. Until then brake
Since hydrodynamic speed of B ₂ is low, no shock caused by hydraulic change. Even if the shift to the first speed is performed in conjunction with the shift of the shift lever position to L, no shift shock occurs.

(11) Shift control related to 1.5th gear (LS).

The first to third speeds turn the sub-transmission 2 low (SL3: off; high / low refers to the range of the output shaft rotation speed of the sub-transmission 2; this low is high in the gear ratio). And SL1
In the fourth speed (0 / D), the sub-transmission 2 is set to high (SL3: ON, the gear ratio is low) and the main transmission 3 is set to the fourth speed (0 / D). Is set to the third speed (SL1, SL2: OFF). The shift between the first to third speeds is thus substantially the main transmission 3
Only the speed stage is switched (single switching speed change).

However, at the 1.5th speed, the auxiliary transmission 2 is set to high (SL3: ON)
In addition, since it is determined by setting the main transmission 3 to the first speed (SL1: off / SL2: on), the 1.5th speed and the second speed
The shift between the third speed and the third speed is a double shift speed in which both the main transmission 3 and the auxiliary transmission 2 are switched.

1 → 1.5 shift FIG. 12a shows the solenoid control timing of the 1 → 1.5 shift. This shift (shift) mode is a single switching shift in which the main transmission 3 switches the sub transmission 2 from low (SL3: off) to high (SL3: on) while maintaining the first speed. In the shift in this shift mode, the timing solenoid SL5 continues to be turned on (energization at an energization duty of 100%). The solenoids SL1 to SL3 switch from ON / OFF that determines the first speed to one that determines the 1.5th speed (see FIG. 3) when the TE period starts (when the timer TB times out). That is, SL3 is switched from off (non-energized) to on (energized).

The linear solenoid SL6 is energized by the energization duty (current value shown in FIG. 9c) corresponding to the throttle valve opening θ and the rotation speed Nt of the output shaft of the auxiliary transmission 2 until the end of the TB period, but enters the TE period. Then, the energization duty is fixed at the immediately preceding value. That is, during the TE period, the current is supplied at a constant duty.

1.5 → 2 shift FIG. 12b shows the solenoid control timing of 1.5 → 2 shift. This shift mode is a double shift speed in which the main transmission 3 is switched from the first speed to the second speed, and the auxiliary transmission 2 is switched from high to low. In this shift mode, first, when the shift is determined, the timing solenoid SL5 is turned off (the energization duty is 0%) (15 to 22 in FIG. 5b), and after the TB period has elapsed, the timing solenoid SL5 has been described with reference to FIG. 11b. An area determination is performed, and energization is performed at an energization duty corresponding to the determined area (148-136 to 144 in FIG. 8A). The linear solenoid SL6 is controlled in the same manner as in the above-described 1 → 1.5 shift.

In this shift mode, the shift solenoid turns off SL1, SL
Switch from 2: ON, SL3: ON (1.5th speed) to SL1: ON, SL2: ON, SL3: OFF (2nd speed).
In the TE period, the CPU first turns on and on SL1 and SL2 for the second speed, respectively, but suspends switching off of SL3. Then, the difference between the subsequent and the rotational speed Nt of the output shaft of the sub transmission 3, a main transmission 3 and the rotational speed 1.53N ₀ bring to N ₀ corresponds with the input shaft (sub transmission 3 of the output shaft) (mainly,
The synchronization deviation) ΔN = Nt-1.53N ₀ between the auxiliary transmission is calculated, whereas, reference values for the rotational speed N ₀ as a parameter (Gmap value: the
13), and when ΔN ≦ Gmap value is satisfied (X
At the point, SL3 is turned off to set the second speed. Fig. 13a shows the Gmap values.

In the 1.5th speed, the auxiliary transmission 2 is set to be high as in 0 / D (fourth speed) and the main transmission 3 is set in the same manner as in the first speed.
The 1.5 shift and the 1.5 → 1 shift can be accomplished by switching from low to high or switching from high to low (switching only one transmission) of the sub-transmission 2 only, but 1.5 → 2 shift or 1.5 → shift The third shift is an upshift in which the sub-transmission 2 is switched from high to low and the main transmission is switched from the first speed to the second speed or the third speed. May occur. Therefore, in this 1.5 → 2 shift, SL3 is switched off to set the second speed at the time (point X) when ΔN ≦ Gmap value is established as described above. This is performed to substantially synchronize the shift completion of the sub transmission 2 and the main transmission 3.

FIG. 13b shows the time chart (1.5 → 2) shown in FIG. 12b.
Shift control) is shown in more detail. In the 1.5 → 2 shift, if SL3 is turned off at the ΔN value shown in FIG. 13c (that is, SL1 is on and SL2 is on, the second speed is set by turning off SL3), the main transmission 3 The completion of the shift of the sub-transmission 2 is substantially synchronized, and there is no shift shock. As shown in FIG. 13c, the ΔN value that provides such a synchronization characteristic uses N ₀ as a parameter, so the Gmap value is set in the rightmost column of FIG. 13c (and in the first column).
As shown in FIG. 3a), the value is about ΔN value. Then the above X point (timing to switch SOL3 off)
At the time when the actual ΔN value becomes equal to or less than the Gmap value (reference value), the shift completion of the main transmission 3 and the sub-transmission 2 is almost always synchronized, and substantially no shift shock occurs.

1.5 → 3 shift This shift mode is a double shift shift in which the main transmission 3 is switched from the first speed to the third speed, and the auxiliary transmission 2 is switched from high to low. The content of this control is the same as the above-described control of 1.5 → 2 shift, but in this shift mode, ΔN = Nt−
And 1.00 × N _0.

1.5 → 4 shift FIG. 12c shows the control timing at the time of shifting in this shift mode. In this shift mode, the main transmission 3 is switched from the first speed to the third speed, and the auxiliary transmission 2 is a single-shift speed in which the high speed is maintained. In this case, when the shift in this shift mode becomes necessary, when the timer TB is started, the timing solenoid SL5 is turned off (the energization duty is 0).
%) (15 to 22 in FIG. 5b), and continues to be turned off even after the shift is completed (the TE period ends). The ON (energization) / off (non-energization) of the solenoids SL1 to SL3 is switched when the TE period starts. The energization duty control of the linear solenoid SL6 is the same as in the above-described 1 → 1.5 shift.

1.5 → 1 shift The control timing at the time of shifting in this shift mode is 12d
Shown in the figure. In this shift mode, the sub transmission 2 is switched from high to low, and the main transmission 3 is a single switching in which the first speed is maintained. In this shift mode, the timing solenoid SL5 continues to be turned off (energization duty 0%),
The ON / OFF of the solenoids SL1 to SL3 is switched to the one that determines the first speed when the TE period starts. Linear solenoid
SL6 maintains the energization duty (the second duty) corresponding to the throttle valve opening θ and the rotation speed Nt of the output shaft of the auxiliary transmission 2 even during the TE period.
(Current value shown in Fig. 9c).

2 → 1.5 shift The control timing at the time of shifting in this shift mode is 12e.
Shown in the figure. In this shift mode, the main transmission 3 is downshifted from the second speed to the first speed, and the subtransmission 4 is shifted up from low to high. In this shift mode, the solenoids SL1 and SL2
On / off of second gear to 1.5th gear (main transmission 3
Switch to the 1st speed), but the solenoid SL
3 means that after the elapse of T15S (0.4 sec), that is, the timer T4 (0.4se
When c) times out, it switches from off (low in the subtransmission 2) to on (high). That is, when entering the TE period, the first speed is set first, and then after the lapse of T15S, the first speed is set.
Set the fifth speed. The timing solenoid SL5 continues to be off (the energization duty is 0%) until TDL (2 sec) elapses after entering the TE period, and is switched on (the energization duty is 100%) after the TDL elapses. Linear solenoid SL6
Is energized even during the TE period with the energization duty (current value shown in FIG. 9c) corresponding to the throttle valve opening θ and the rotation speed Nt of the output shaft of the auxiliary transmission 2.

3 → 1.5 shift The control timing at the time of shifting in this shift mode is set to 12f.
Shown in the figure. This shift mode is a double-shift operation in which the main transmission 3 is downshifted from the third speed to the first speed, and the subtransmission 2 is shifted up from low to high. The contents of this control are the same as the above-described control of 2 → 1.5 shift.

4 → 1.5 shift The control timing at the time of shifting in this shift mode is 12g.
Shown in the figure. In this shift mode, the main transmission 3 is switched from the third speed to the first speed, but the subtransmission 2 is a single-shift speed in which the high speed is maintained. However, as shown in FIG. To the third speed (switch the subtransmission 2 from high to low = switch SL3 from on to off). And T
After the E period, timer T2 (0.2 sec) and timer T2D (0.2
+ TDLsec: TDL is a delay time) and starts (55 in FIG. 5c).
To 63), set to 1.5th speed when timer T2 expires (70 to 79 in Fig. 5e. SL3: off → on, SL2: off →
ON, that is, switching the auxiliary transmission 2 from low to high,
And the main transmission 3 is switched from the third speed to the first speed). The timing solenoid SL5 continues to be turned off (energization duty 0%) until the timer T2D times out, and the timer T2D
Is turned on (100% energization duty) when the time is over (72-76 in FIG. 5e; ATIN is an output register addressed to SL5). The linear solenoid SL6 keeps the throttle valve opening θ and the rotation speed Nt of the output shaft of the subtransmission 2 even during shifting.
(The current value shown in FIG. 9c).

(12) Regular lock-up control.

In the “lock-up control” (67) of FIG. 5d, when the lock-up (direct connection clutch 50 contact: solenoid SL4 is on) is not performed (SL4 off), the shift lever position is D and the brake switch 137 is off (open). : No brake pedal is depressed), and a reference vehicle speed data group using the throttle valve opening θ as a parameter for lock-up engagement determination corresponding to the speed stage is specified. those which correspond to the throttle valve opening θ identifies (reference vehicle speed data), it is checked whether the current vehicle speed N ₀ is the reference vehicle speed data or more. Since the current vehicle speed N ₀ is in a certain lockup principal at the reference speed data above, energizing the solenoid SL4 (the lockup) is, in order to prevent the shock by the lock-up, the energization duty of the SL4, the 14a Figure As shown in the figure. That is, when it is determined that lockup is necessary, the energization duty Dt1 corresponding to the current throttle valve opening θ is determined and written into the output register ALIN. FIG. 14b shows the relationship between the opening degree θ and Dt1.
Then, the timer TLB (0.4 sec) and TLON (1.0 sec) are started. Thereafter, under the condition that the lock-up condition is satisfied, the same energization duty is maintained until the timer TLB times out. When the timer TLB expires, the energization duty Dt1 (FIG. 14b) corresponding to the throttle valve opening θ at that time is calculated again, and the energization duty is updated to the current calculation value. And a timer
When TLON times out, the energizing duty is set to 100%
Switch to (ON). This completes the lock-up engagement (connection of the direct coupling clutch 50) control.

When the vehicle is in lock-up (direct connection clutch 50 contact) and when the above-described lock-up engagement control is being performed, a reference vehicle speed data group using the throttle valve opening as a parameter for lock-up release determination corresponding to the speed stage is specified. , Data (reference vehicle speed data) corresponding to the current throttle valve opening θ in the data group is specified, and the current vehicle speed is determined.
Check if N ₀ is less than or equal to the reference vehicle speed data. If the current vehicle speed N ₀ is lower than the reference vehicle speed data, it is necessary to release lock-up, so the solenoid SL4 is turned off (the energization duty 0
%) (Write data specifying the energization duty of 0% to the output register ALIN addressed to the solenoid SL4). However, in order to avoid frequent repetition of lock-up input and release, the above-described determination of the necessity of lock-up release is not performed for 0.5 sec from the end of lock-up input control (time-out of timer TLON).

During the lock-up input control, the timer TLON
If the lock-up release is required before the time expires, SL4 is immediately turned off (the energization duty is 0%).
If a shift is required before the timer TLB times out, S
Turn off L4 immediately. Further, if a shift is required before the timer TLB times out and the timer TION has not yet timed out, the following control (13) is performed.

(13) Energization control of the lock-up control solenoid SL4 when a gear shift occurs during lock-up (direct connection clutch 50 contact).

During the TE period of the shift control of the upshift, the CPU of the control board 130 reduces the energization duty of the lock-up closing solenoid SL4 as shown in FIG. 14c so that the torque converter 1 absorbs the shift shock to some extent. When the TE period elapses, the duty ratio becomes 10
Return to 0%. That is, in the TE period, first, the energization duty of the lock-up closing solenoid SL4 is reduced to Dt2 corresponding to the throttle valve opening θ at that time, and the timer TLS (0.4 sec) is started.

FIG. 14d shows the throttle valve opening θ and the energizing duty D.
This shows the relationship with t2. Then, the timer TLS waits for a time over, and when the time is over, the energization duty Dt2 (FIG. 14d) corresponding to the throttle valve opening θ at this time is calculated again, and the energization duty of the solenoid SL4 is updated to this calculated value. When the TE period ends, the solenoid SL4
To 100%.

In the case of a downshift, the SL4
Is turned off (the energization duty is 0%). Thereafter, if the requirement is satisfied by the above (12), lock-up is performed.

(14) Lock-up control linked to changes in shift lever position, etc.

When the brake switch 137 is turned on (the brake pedal is depressed) or when the shift lever position is switched to S, L, N, R or P, the lockup is immediately released (SL4 off). .

When the shift lever position is S, N ₀ ≧
When the three conditions of 700 rpm, the closing of the idling switch 139 (idling), and Ne <Nt are satisfied at the same time, lock-up is established by the lock-up closing control described in (12) above, and the shift lever position is shifted from S by another range. , When N ₀ <700 rpm, or
When the idling switch 139 is opened (the throttle valve is opened), the lockup is immediately released (SL4 is turned off).

As described above, the CPU of the control board 130 sets the shift lever position (position detection of the switch 134) to the LS in the L range.
When the (1.5th speed) instruction switch 131 is closed (1.5th speed is designated), 1 is written into the register LSF (7-11-12), and in the "shift determination" (14), the content of the register LSF is 1 Sometimes, the 1.5th speed is set in the register DS as the next speed stage to be set.
When the current gear (contents of the register PS) is different from the 1.5th speed of the register DS, it is determined that a shift is necessary (1
5), current speed stage (first speed, second speed, third speed or fourth speed)
To the 1.5th speed (FIGS. 12a, 12e, 12f or 12g).

Thereafter, when the switch 131 is opened (1.5th speed is not specified), or when the shift lever position is switched from the L range to the S range or the D range, the register LSF is cleared (synonymous with writing 0: 7, 11). -13), "shift determination" (1
In step 4), the speed stage (X stage) corresponding to the current throttle valve opening θ and the wheel drive shaft rotation speed N ₀ among the speed stages defined by the S range or the D range is determined and registered in the register. The data is written into DS, and a 1.5 → X shift (X = 1, 2, 3, or 4; FIG. 12b, FIG. 12c, FIG. 12d) is performed.

Thereafter, when the shift lever position is in the D range, only the first, second, third, and fourth speeds are changed, and when the shift lever position is in the S range, the shift between the first and second speeds is performed. If only the shift is performed and the switch 131 is open (the 1.5th speed is not specified), only the first speed is set in the L range.

 In any case, the 1.5th gear is not set.

〔The invention's effect〕

As described above, according to the first aspect of the present invention, in the shift to the first speed at which the maximum torque is transmitted, the timing control is performed until the shift to the first speed is completed as shown in FIG. 11g. Since the oil pressure to the brake (B ₂ ) is set to a low pressure by the valve (SL5), no shift shock to the first speed occurs.

When the shift to the 1st speed is completed, the timing control valve (SL5)
Provides high pressure to the brake (B ₂ ) to provide maximum torque transmission, and a first speed, maximum torque transmission characteristic is established.

According to the second invention of the present application, D or S range to L
When the range is switched, the hydraulic pressure is not immediately switched to the high pressure for transmitting the maximum torque, but is performed after a predetermined time (T20a = 2 seconds). Does not occur.

In addition, since such pressure adjustment is performed by the timing control valve (SL5) that is electrically energized, when a predetermined time (2 seconds = T20a; 149 to 155 in FIG. 8a) elapses accurately. The timing control valve (SL5) switches accurately,
The time until the switching is not affected by the fluctuation of the oil temperature or the load.

Since the time until the switching is accurate as described above, there is no shock due to the time lag.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a transmission mechanism according to an embodiment of the present invention. FIG. 2 is a block diagram showing a hydraulic circuit for supplying or removing hydraulic pressure to various brakes and clutches of the transmission mechanism shown in FIG. FIG. 3 shows a relationship between a combination of energization / de-energization of solenoid valves SL1 to SL3 for determining a speed stage of the hydraulic circuit shown in FIG. 2 and engagement / disengagement of various brakes and clutches shown in FIG. It is a top view. FIG. 4 is a block diagram showing an outline of an electric circuit configuration for energizing the solenoid valves SL1 to SL3, the solenoid valve SL4 for lock-up control, the timing solenoid valve SL5, and the linear solenoid valve SL6 shown in FIG. Figures 5a, 5b, 5c, 5d and 5e
4 is a flowchart showing a control operation (main routine) of the microcomputer of the control board shown in FIG. 6a and 6b are flowcharts showing the contents of “detection of TSO, TSE” (64) shown in FIG. 5d. FIG. 7 shows the “linear solenoid control” (6
It is a flowchart which shows the content of 5). 8a and 8b are flowcharts showing the contents of the “timing solenoid control” (66) shown in FIG. 5d. FIG. 9a is a time chart showing a shift determination, a shift output, and a shift completion timing executed by the microcomputer of the control board 130 shown in FIG. FIG. 9b is a graph showing a relationship between an energizing current value of an electric coil of the linear solenoid valve SL6 shown in FIG. 2 and a hydraulic pressure output by the valve SL6. The 9c figure, a microcomputer of the control board 130 shown in FIG. 4 is a throttle valve opening θ and the clutch C ₁
7 is a graph showing a current value to be supplied to the linear solenoid valve SL6, which is determined based on the drum rotation speed Nt of FIG. FIG. 10a shows the determination of the energization duty value of FIG.
9 is a graph showing a correction value K11 corresponding to an oil temperature used in 8). FIG. 10b shows the determination of the energization duty value of FIG.
Correction value K12 corresponding to throttle valve opening θ used in 8)
5 is a graph showing the value of. FIG. 10c shows the determination of the energization duty value of FIG.
9 is a graph showing a correction value K2 corresponding to a shift mode and a throttle valve opening θ used in 8). FIG. 10d is a graph showing a relationship between a mechanical shift time reference value TS corresponding to the throttle valve opening θ and a region division based on the reference value. The 11a diagrams, when the 2 → 3 shift, a graph showing a hydraulic variation of the brake B ₀ and the clutch C ₂ shown in FIG. 1 shows the case of a power-on shift is solid. Figure 11b is a graph showing the area division of the throttle valve opening θ and the wheel drive shaft rotational speed N _0. The energization duty of the timing solenoid SL5 shown in FIG. 2 is determined corresponding to this area. FIG. 11c is a time chart showing the energization duty switching timing of the timing solenoid valve SL5 shown in FIG. 2 when shifting from the third speed or the fourth speed to the second speed by power-on. FIG. 11d is a graph showing one example of the area division shown in FIG. 11b. FIG. 11e is a graph showing the relationship between the area shown in FIG. 11d and the energization duty determined corresponding thereto. FIG. 11f shows the brake shown in FIG. 1 brought about by the energization duty setting shown in FIG.
It is a graph showing a hydraulic rising characteristics of B _1. The 11g figure, when the 2 → 1 shift is a graph showing a hydraulic rise characteristic of the brake B _2. 12a, 12b, 12c, 12d, 12e, 12f
FIG. 12G and FIG. 12G show the on / off switching timing and the timing solenoid valve SL5 of the speed stage setting solenoid valve SL3 shown in FIG. 2 when shifting from the 1.5th speed to another speed stage or vice versa. 6 is a time chart showing the on / off switching timing of the switch. FIG. 13a is a plan view showing data referred to for determining the ON / OFF switching point X of the solenoid valve SL3 for setting the speed stage shown in FIG. 12b. FIG. 13b is a view showing the first state at the time of the 1.5 → 2 shift shown in FIG. 12b.
4 is a graph showing brake pressure changes of brakes B _{0 to} B ₂ shown in FIG. The 13c figure, when the 1.5 → 2 shift that shown in 12b view, no substantial shift shock, is a plan view showing the change in the rotational speed of the output shaft rotational speed N ₀ corresponding clutch C ₁ drum. FIG. 14a is a time chart showing a time-series change in the energization duty of the solenoid valve SL4 when the direct coupling clutch 50 shown in FIG. 1 is engaged (locked up). FIG. 14b is a graph showing the energizing duty for urging the solenoid valve SL4 assigned to Dt1 shown in FIG. 14a, which is determined corresponding to the throttle valve opening θ. FIG. 14c is a time chart showing adjustment of the energization duty of the solenoid valve SL4 for reducing shift shock during shifting while the direct coupling clutch 50 shown in FIG. 1 is engaged. FIG. 14d is a graph showing the energization duty for urging the solenoid valve SL4 assigned to Dt2 shown in FIG. 14c, which is determined corresponding to the throttle valve opening θ. FIG. 15a is a graph showing a reference vehicle speed value group for determining whether or not a shift is necessary when the economy mode is not designated in “shift determination” (14) shown in FIG. 5a. FIG. 15b is a graph showing a reference vehicle speed value group for determining whether or not a shift is necessary when the economy mode is designated in “shift determination” (14) shown in FIG. 5a. 1: Torque converter 2: Sub-transmission 3: Main transmission (automatic transmission) SL1, SL2: Solenoid valve for setting speed stage SL3: Solenoid valve for setting speed stage SL4: Solenoid valve for setting lock-up SL5: Timing solenoid valve (Timing control valve) SL6: Linear solenoid valve (Pressure control valve) 50: Direct coupling clutch 60: 2-3 shift timing valve 70: Drain pressure valve 80: Orifice control valve 81, 82: Orifice 90: Modulator valve 100 : Oil reservoir 101: Hydraulic pump 102: Main pressure regulating valve 103: Secondary pressure regulating valve 104, 105, 132: Flow path 110: Accumulator pressure control valve 200: Manual valve (manual valve) 220: 1-2 shift valve 230: 2-3 shift valve 240: 3-4 shift valve 250: low coast modulator valve 260-290: accumulator 360: lockup control valve 370: lockup signal valve 130: control board (shift control Means: timing control means) 131: 1.5th speed instruction switch 132: economy mode instruction switch 133: 4th speed inhibition switch 134: shift lever position detection switch (position detection means) 135: water temperature sensor 136: oil temperature sensor 137: brake Switch 138: Throttle valve opening sensor 139: Idling detection switch 140: Pulse generator 141: Pulse generator 142: Pulse generator 163, 164: In-vehicle battery IGS: Ignition key switch

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-48-77258 (JP, A) JP-A-62-159844 (JP, A) JP-A-49-121072 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (2)

(57) [Claims] 1. An automatic transmission interposed between an output shaft of an engine and a load drive shaft for shifting at least a first, second and third gear ratio, a brake for the automatic transmission and A hydraulic circuit for selectively supplying hydraulic pressure to the clutch and selectively releasing hydraulic pressure therefrom, an accumulator connected to the brake and the clutch in the hydraulic circuit, a pressure control valve for adjusting a back pressure of the accumulator, and A shift control means for determining whether or not a shift is necessary and performing a shift when a shift is required, in order to switch only the hydraulic pressure applied to the brake engaged in the first speed between a high pressure and a low pressure. A timing control valve that is turned on / off by an electric bias; a modulator valve that applies a regulated high pressure to the timing control valve; and Timing control means for energizing the electric power, setting the shift control means to start shifting to the first speed and providing a low pressure until the shift is completed, and then setting the shift to a high pressure after the end. A hydraulic control device for an automatic transmission, characterized in that: 2. An automatic transmission interposed between an output shaft of an engine and a load drive shaft and configured to shift at least a first, second, and third gear ratio, and a gear ratio of the automatic transmission. A first position and a second position for setting the speed in a low speed range including the first speed.
Second for defining the speed range including the third speed and the third speed
A manual valve having at least two positions, a hydraulic circuit for selectively supplying and removing hydraulic pressure from brakes and clutches of the automatic transmission; A hydraulic control device for an automatic transmission, comprising: an accumulator connected to a clutch, a pressure control valve for adjusting a back pressure of the accumulator, and shift control means for determining whether or not shifting is necessary and performing shifting when shifting is required: Position detecting means for detecting the position of the manual valve; a timing control valve that is turned on / off by an electric bias for switching only a hydraulic pressure applied to a brake engaged in a first speed between a high pressure and a low pressure; A modulator valve for applying a regulated high pressure to the valve; and from a second position to a first position detected by the position detecting means. And a timing control means for updating the on / off of the timing control valve to a value that provides a high pressure after a predetermined time in response to the switching of the automatic transmission.